1. Field of the Invention
The present invention relates to a control system for a four wheel drive vehicle and more particularly to a control system for preventing a four wheel drive mechanism from incorrect transmission of the power of an internal combustion engine or for generating warning signals upon such incorrect operation.
2. Description of the Prior Art
Conventionally a four wheel drive mechanism has a transfer, a front propeller shaft, a rear propeller shaft and a power assist arrangement communicating with a vacuum pump through a solenoid valve. The power of an internal combustion engine is selectively transmitted through the transfer to the front propeller shaft and/or the rear propeller shaft.
When the power delivered to either the front or rear propeller shaft is transmitted at speed to both front and rear propeller shafts, a drive hub comes in contact with a splined chamfer of a sleeve. The contact between the hub and the splined chamfer generates noise or strange sounds, causes increased wear on the parts and may destroy part of the contacting surfaces.